1. Field of the Invention
The present invention relates to a bicycle. More particularly, the present invention relates to a bicycle with a common pivot shock absorber.
2. Description of the Related Art
Refer to FIG. 1. Generally, a bicycle 1 comprises a frame 11 and a shock absorber 12. The frame 11 has a seat tube 111, a front triangle 112 connected with the seat tube 111 and extended forwardly, a link 113 mounted pivotally between the seat tube 111 and the front triangle 112, a rear triangle 114 connected pivotally to the link 113 and extended backwardly, and a pair of mounting ears 115 secured on the front triangle 112. The shock absorber 12 comprises a cylinder 121 and a retractable piston rod 122. The cylinder 121 and the piston rod 122 are respectively, pivotally and movably connected to the link 113 and the mounting ears 115 on the front triangle 112 with their opposite ends. Thus, the shock absorber 12 is actuated by the relative motions between the front triangle 112 and the rear triangle 114 and absorbs the amplitude of shocks by retracting operations to provide shock absorbing effects.
However, connecting pivotally the front triangle 112, the rear triangle 114 and the shock absorber 12 together needs not only using the link 113, but also a first pivot point A and a second pivot point B that are located respectively among the rear triangle 114, the seat tube 111 and the link 113, a third pivot point C and a fourth pivot point D that are located respectively among the link 113, the shock absorber 12 and the frame 11, and a fifth pivot point E located between the shock absorber 12 and the front triangle 112. In other words, the aforementioned components have five pivot points, i.e. A to E. Therefore, a large number of pivoting connecters are needed, which brings complex manufacturing procedures, difficult assembly and repair, and high manufacturing costs.
Further, since one end of the cylinder 121 of the shock absorber 12 is pivotally and movably connected to the link 113, and the link 113 blocks the retracting path between the shock absorber 12 and the seat tube 111, the cylinder 121 of the shock absorber 12 will interfere with the link 113 and the seat tube 111 when the cylinder 121 retracts along the retracting path. Thus, the piston stroke is restricted so that the shock absorbing effects are also limited, which renders the suspension system unable to meet the demands.